Re: [PATCH 04/11] accel: ethosu: Ensure SRAM size is 0 on mapping failure

[Frank Li]

On Thu, Aug 27, 2026 at 03:33:03PM -0500, Rob Herring (Arm) wrote:
> On a mapping failure of the SRAM, the SRAM size is left as non-zero. The
> probe will succeed as the error return is not checked since having SRAM is
> not a hard requirement. The non-zero size allows jobs to access SRAM which
> is left pointing to physical base address 0x0.
>
> Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>  drivers/accel/ethosu/ethosu_drv.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/accel/ethosu/ethosu_drv.c b/drivers/accel/ethosu/ethosu_drv.c
> index d121fb0d7732..f1af7b3ea038 100644
> --- a/drivers/accel/ethosu/ethosu_drv.c
> +++ b/drivers/accel/ethosu/ethosu_drv.c
> @@ -281,8 +281,6 @@ static int ethosu_device_suspend(struct device *dev)
>
>  static int ethosu_sram_init(struct ethosu_device *ethosudev)
>  {
> -	ethosudev->npu_info.sram_size = 0;
> -
>  	ethosudev->srampool = of_gen_pool_get(ethosudev->base.dev->of_node, "sram", 0);
>  	if (!ethosudev->srampool)
>  		return 0;
> @@ -293,6 +291,7 @@ static int ethosu_sram_init(struct ethosu_device *ethosudev)
>  							     ethosudev->npu_info.sram_size,
>  							     &ethosudev->sramphys);
>  	if (!ethosudev->sram) {
> +		ethosudev->npu_info.sram_size = 0;
>  		dev_err(ethosudev->base.dev, "failed to allocate from SRAM pool\n");
>  		return -ENOMEM;
>  	}
>
> --
> 2.53.0
>